针对蒙西地区220kV同塔四回路典型输电线路段,采用有限元方法模拟研究杆塔在随机风作用下的结构强度和疲劳寿命。利用ABAQUS有限元软件建立塔线耦合体系有限元模型,考虑蒙西地区地形特点,采用数值方法模拟生成随机风场,计算塔线体系的动力响应。根据计算结果确定杆塔的危险区域,建立该局部三维实体有限元模型,并与其他部分的杆梁模型组合为实体与杆梁混合模型。提取塔线体系在随机风作用下导地线挂点的支反力时程曲线,模拟实体与杆梁混合模型的动力响应。模拟研究了两种风速和不同螺栓预紧力情况下杆塔结构强度,并分析了随机风激励下杆塔的疲劳寿命。结果表明,螺栓的松弛对杆塔强度和疲劳寿命影响明显,可能是引起杆塔破坏的主要原因。

With a typical section of 220kV four circuit transmission line in West Inner Mongolia, the structural strength and fatigue life of the towers under stochastic wind are numerically studied by means of the finite element (FE) method. The FE model of the tower-line system is established using the ABAQUS software. Considering the topographic characteristics of the West Inner Mongolia, stochastic wind fields are simulated numerically to calculate the dynamic response of tower-line system. According to dynamic responses of the tower-line system under wind load, the dangerous zone of the tower is determined and its 3D solid FE model is set up. A hybrid FE model combined the local 3D model with the spatial beam model of the other portion of the tower is constructed. The time histories of the reaction forces at hanging points of the conductors and ground wires are applied on the hybrid FE model of the tower to simulate its dynamic responses under wind load. The structural strength and fatigue life of the tower under two stochastic wind fields and with different bolt preloads are numerically investigated. The results show that the bolt looseness affect the strength and fatigue life of the tower obviously and may be one of the main reasons of tower failure.

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内蒙古电力公司科技项目(2020-39)